Email Usage Guide

Quick Summary

Email quota per account	8 GB for staff (Exchange) 4 GB for students Click here to check your mailbox usage
Spam Detection	Spam detection will be turned on by default for new accounts created on or after 6 Sept 2012. Users can choose to turn on / turn off Spam Detection, or adjust the detection level.
If quota reached the threshold limit	Exchange Users: Shall receive quota warning mail when usage exceeded 95% of the quota limit. Cannot send / receive mail when mailboxes is 100% full and sender shall receive bounce back message. iMail Users: When usage exceeded 95% of the quota limit, "95% Warning" will be displayed when users browse their mailboxes. Delivery of the incoming message will be tried for 3 days before bouncing back to sender in the first 90 days of the "95% Warning" alert. After consecutive 90 days reaching the 95% limit, incoming message (larger than user's available disk space) will be bounced back to the sender immediately.
Maximum size of outgoing message	50 MB
Maximum no. of recipients per outgoing message	200 email addresses
New mail notification polling interval	no shorter than 5 minutes

Details

Email quota per account

The default quota is 8 GB for staff (Exchange) and 4 GB for students, click here on how to check your mailbox usage.

This quota is imposed to include both INBOX and all other mail folders.

Spam Detection

Accounts created before 6 Sept 2012: Will only be effective after explicitly turned on by the user.

Accounts created on or after 6 Sept 2012: Spam Detection is turned on by default with medium detection level.

User can choose to turn on / turn off Spam Detection, or adjust the detection level.

If quota exceeds ...

Exchange Users:

Shall receive quota warning mail when usage exceeded 95% of the quota limit.

Cannot send / receive mail when mailboxes is 100% full and sender shall receive bounce back message.

iMail Users:

When usage exceeded 95% of the quota limit, "95% Warning" will be displayed when users browse their mailboxes (on clients which support IMAP ALERT command e.g. Thunderbird, etc.)

Incoming emails that exceed the quota will be spooled up and retried by server in the first 90 days of the "95% Warning" alert. If it can't be delivered in 3 days from first reception, the mail will then bounce to the sender for the undelivered reason of over quota.

After consecutive 90 days reaching the 95% limit, incoming message (larger than user's available disk space) will be bounced back to the sender immediately

Users are advised to keep monitoring your mailbox usage to avoid any late delivery of incoming emails.

Besides, it is suggested for you to archive or backup any less frequent access mailbox to local storage.

Maximum size of outgoing message

The email server is configured to restrict the size of all outgoing messages to a maximum of 50 MB.

Maximum of 100 MB among Exchanges users.

Maximum no. of recipients per outgoing message

Only 200 recipients are accepted per message in an SMTP transaction. If you require to send email to a recipient lists more than 200, you are advised to use our mailing list service.

New mail notification polling interval

As most of the new mail notification tools are establishing new IMAP/POP connection for checking new mail, too frequent checking will surely degrade our overall performance and cause others users to suffer. The suggested time interval should be no shorter than 5 minutes.